Implementing Tagging in Textpattern

I’ve just spent the evening knocking up basic folksonomy/”tag” support in Texpattern. So far, I can produce a list of all tags used across all articles or for a specific article, build weighted lists and count how many articles use a certain tag. Currently I’m building the “list articles by tag” function.

So far during implementation, I have used a custom field to store the tags. Then it hit me that that existing keywords field might be a more logical choice. I can think of advantages/disadvantages to either. Truth be told, I’m leaning towards using the keyword field – I see tags and keywords as pretty much the same thing, but I realise others may see it differently.

So which field do you think is most suitable? Which one would you prefer to use when writing an article?